cauldron vs stockpot

cauldron

noun
  • A large bowl-shaped pot used for boiling over an open flame. 

  • A strategic encirclement. 

stockpot

noun
  • A large pot, such as is used for making stock or for cooking large amounts of soup. 

How often have the words cauldron and stockpot occurred in a corpus of books? (source: Google Ngram Viewer )